Countdown and live coverage of the SpaceX Falcon 9 rocket at Spaceport 40 at Space Force Station in Cape Canaveral, Florida. The Starlink 4-20 mission will launch SpaceX’s next batch of 51 Starlink broadband satellites and Boeing’s carpool payload to demonstrate broadband communications technology.follow us Twitter.
SpaceX is counting down the launch of 51 Starlink internet satellites and a carpool payload that will maneuver into different orbits using an orbital transfer vehicle built by Spaceflight to test Boeing’s broadband communications technology.
The launch on a Falcon 9 rocket from Spaceport 40 at the Cape Canaveral Space Force Station is scheduled for Sunday at 10:09 p.m. ET (Monday 0209 GMT), marking SpaceX’s 40th launch of the year launch.
According to the U.S. Space Force’s 45th Weather Squadron, Sunday night’s launch has an 80 percent chance of favorable weather.
The primary payload for Sunday night’s mission, designated Starlink 4-20, is SpaceX’s next batch of Starlink internet satellites. The rocket will launch 51 flat-packed Starlink spacecraft, less than a typical Starlink launch from Florida, to accommodate a carpool payload.
The secondary passenger is a chemically propulsive Sherpa-LTC rail transfer vehicle aboard the Starlink payload stack inside the Falcon 9 payload fairing. The Sherpa-LTC orbital transfer vehicle, built by Seattle-based spacecraft developer and ride-sharing launch broker Spaceflight, is designed to transport small satellites to various altitudes and inclinations and conduct experiments after first entering orbit from larger rockets.
The Sherpa-LTC orbital transfer vehicle on the Starlink 4-20 mission will carry Boeing’s Varuna Technology Demonstration Mission or Varuna-TDM. The mission is to demonstrate technology and conduct in-orbit performance testing for the V-band communications system, a proposed 147-satellite constellation designed to provide broadband connectivity to commercial and U.S. government users.
The Varuna-TDM mission will provide potential users of the broadband satellite constellation “an opportunity to evaluate V-band communications link performance and determine its attributes and acceptability for specific applications,” Boeing said.
The Falcon 9 rocket will deploy the Sherpa-LTC transfer vehicle with the Varuna Technology Demonstration Mission to a near-circular orbit at an average altitude of about 192 miles (310 kilometers) above Earth and an inclination of 53.2 degrees from the equator .
Sherpa-LTC will first deploy after approximately 49 minutes of flight, and then separate the 51 Starlink satellites at T++72 minutes.
Spaceflight’s solar-powered orbital transfer vehicle will perform a series of burns to reach a circular orbit 620 miles (1,000 kilometers) above Earth, where the Varuna technology demonstration mission will take place. The Varuna technology demonstration payload was designed and built by Astro Digital, which also provides the command and control system for the Sherpa-LTC rail transfer vehicle.
The Sherpa-LTC vehicle uses a dual-propellant, “green” or non-toxic propulsion system developed by Benchmark Space Systems.
“Sherpa-LTC’s transport capabilities combined with the reliability and consistency of Starlink missions create an ideal solution for our customers’ unique mission needs,” said Spaceflight CEO and President Curt Blake. “Our OTV removes the more challenging hurdles of getting spacecraft into uncommon orbits at LEO and beyond. We are eager to continue delivering innovative, cost-effective and reliable space to our customers and partners like Astro Digital shipment service.”
Through Sunday’s Starlink 4-20 mission, SpaceX has launched 3,259 Starlink internet satellites, including prototypes and test cells that are no longer in use. Sunday night’s launch will be SpaceX’s 59th mission, primarily dedicated to putting the Starlink internet satellite into orbit.
SpaceX’s launch team, based in the launch control center south of the Cape Canaveral Space Force Station, will begin loading the 229-foot-tall (70-meter) Falcon 9 with ultra-cold, dense kerosene and liquid oxygen propellant in the rocket. 35 minutes.
Helium will also flow into the rocket during the last half-hour of the countdown. In the final seven minutes before takeoff, the Falcon 9’s Merlin main engines will be thermally conditioned to fly through a procedure called “cooling.” The Falcon 9’s guidance and range safety systems will also be configured for launch.
After liftoff, the Falcon 9 rocket will direct its 1.7 million pounds of thrust—generated by nine Merlin engines—to the northeast over the Atlantic Ocean.
The rocket will surpass the speed of sound in about a minute, then shut down its nine main engines two and a half minutes after liftoff. The booster stage will be released from the Falcon 9’s upper stage, which will then fire pulses from cold gas control thrusters and extended titanium mesh fins to help guide the vehicle back into the atmosphere.
Two brake burns slowed the rocket’s landing on the drone ship “Just Read the Instructions” about 400 miles (650 kilometers) after takeoff, about eight and a half minutes after takeoff.
The first stage of Sunday’s launch is designated B1052 in SpaceX’s inventory. The booster will make its seventh spaceflight. The vehicle flew as a side booster on two Falcon Heavy missions in 2019 before being converted to fly the first stage of a Falcon 9 rocket earlier this year.
The Falcon 9’s reusable payload fairing will be discarded during the second stage burn. A recovery vessel is also stationed in the Atlantic to retrieve the nose cone halves after being splashed under a parachute.
The first-stage landing of Sunday’s mission will land immediately after the Falcon 9’s second-stage engines shut down to put the Starlink satellite into a preliminary transfer orbit. A second burn of the upper stage, approximately 45 minutes after launch, will bring the payload into proper orbit for separation.
After the Sherpa-LTC payload is released, the upper stage will release the holding rod from the Starlink payload stack, allowing the flat-packed satellite to fly freely in orbit from the Falcon 9’s upper stage. 51 The spacecraft will deploy the solar array and operate through automated activation steps, before maneuvering into its operational orbit using a krypton-fueled ion engine.
The satellite will use onboard thrusters to do the rest to reach a circular orbit 335 miles (540 kilometers) above Earth.
Starlink satellites will fly in one of five orbital “hulls” of varying inclinations of SpaceX’s global internet network. After reaching its operational orbit, the satellite will enter commercial service and begin sending broadband signals to consumers, who can purchase Starlink service and connect to the network through ground terminals provided by SpaceX.
Rocket: Falcon 9 (B1052.7)
Payload: 51 Starlink satellites and Sherpa-LTC (Starlink 4-20)
Launch Location: SLC-40, Space Force Station, Cape Canaveral, Florida
Launch Date: September 4, 2022
Launch time: 10:09 PM ET (0209 GMT)
Weather forecast: 80% chance of acceptable weather; low risk of upper-level winds; low risk of booster recovering from adverse conditions
Booster Recovery: ‘Just Read the Instructions’ Drone Ship East of Charleston, South Carolina
Launch Azimuth: northeast
Target Orbit: 188 miles x 196 miles (304 km x 316 km), 53.2-degree inclination
- T+00:00: Take off
- T+01:12: Maximum Aerodynamic Pressure (Max-Q)
- T+02:29: Level 1 mainframe shutdown (MECO)
- T+02:33: Stage separation
- T+02:39: Second stage engine ignition (SES 2)
- T+03:13: Fairing jettisoned
- T+06:05: The first stage enters combustion ignition (three engines)
- T+06:36: The first stage enters the combustion cut-off
- T+08:05: First stage landing combustion ignition (one engine)
- T+08:27: First stage landing
- T+08:45: Second stage engine shutdown (SECO 1)
- T+45:25: Second stage engine ignition (SES 2)
- T+45:27: Second stage engine shutdown (SECO 2)
- T+49:28: Sherpa-LTC separation
- T+1:12:23: Starlink satellite separation
- 174th Falcon 9 launch since 2010
- 182nd Falcon series launch since 2006
- Seventh launch of Falcon 9 booster B1052
- 149th Falcon 9 launch from Florida’s Space Coast
- The 96th Falcon 9 launches from Pad 40
- 151st launch from pad 40
- The 116th flight of the reused Falcon 9 booster
- 59th dedicated Falcon 9 launch using Starlink satellites
- 40th Falcon 9 launch in 2022
- SpaceX’s 40th launch in 2022
- 38th orbital launch attempt at Cape Canaveral in 2022
Email the author.
Follow Stephen Clark on Twitter: @Stephen Clark 1.